1. Field of the Invention
The present invention relates generally to smoker's pipes, and more particularly, to a new and improved smoker's pipe of the dry bowl type using auxiliary and cooling air flows.
2. Description of the Prior Art
Conventional pipes, including filtered pipes and those equipped with metal fittings which form condensation and taint flavor, function today the same way they have for centuries. A single channel, closed at the heel end, connects the bowl, shank, stem and bit. Liquids generated while smoking run down this single channel and build up in the heel of the bowl. Filters and fittings in the smoke channel slow or modify the process, but eventually the liquids will enter the bowl and will be absorbed by the tobacco. This condition generally continues until about one-fourth of the tobacco in the lower bowl becomes saturated with collected liquids.
When the burning tobacco in the upper part of the bowl reaches the saturated tobacco in the lower bowl, combustion is gradually reduced as the degree of wetness increases, and the condition becomes akin to that of trying to burn wet leaves. From this level downward, the flavor supporting carbon cake built up on the inner walls of the pipe begins to disintegrate and disappear. Moreover, the heat of descending combustion above this level progressively increases the temperature of the confined liquids, causing excessive heat and accelerating the absorption of contaminants.
These circumstances sustain the development of foul odors and bad taste. In addition, the smoke must pass through this collection of hot, acrid consensate producing a biting sensation on the smoker's tongue.
In my U.S. Pat. No. 3,028,867, a dry bowl pipe is disclosed wherein the bowl and stem are integrally molded of plastic material, and wherein the stem has an additional passage within which a cartridge of absorbant material is disposed so as to collect the liquid combustion products and efficiently remove them from the smoke path. The absorbant cartridge has an outer end screwed into a threaded bore in the front end portion of the stem below the bowl. The cartridge has a flattened nipple whereby it can be grasped exteriorally of the pipe to insert and remove the cartridge which has an axially bored inner end to receive a tube which is fitted in a bore in the mouthpiece. The tube has a radial aperture in its side wall so as to provide a smoke path from the burning tobacco in the bowl to the smoker's mouthpiece.
An improved dry bowl pipe is disclosed in my U.S. Pat. No. 3,422,821 wherein the bowl assembly is composed of an outer bowl of plastic and an inner bowl of ceramic material. The inner surface of the outer bowl is formed with a plurality of narrow vertical ribs that engage the inner bowl and hold it spaced from the outer bowl while creating a plurality of air grooves whereby air can flow over the inner bowl for cooling.
The inner bowl is held in place by a resilient metal split washer which is seated on the upper end of the inner bowl under an annular clamping ring that is screwed into the internally threaded upper end of the outer bowl in engagement with the split washer.
Pipes formed in accordance with my aforesaid patents, have been well received by smokers. They function extremely well to provide a smooth, cool smoke without the foul taste attendant to the operation of conventional smoker's pipes. However, the pipes are somewhat expensive to fabricate because of special structural details including the vertical ribs between the inner and outer bowls, the manner of joining the inner and outer bowls together, and the manner of mounting the absorber cartridge.
However, pipes having an inner bowl of a ceramic material develop a serious problem whereby moisture travels transversely through the ceramic bowl and accumulates as droplets on the outer side thereof. In addition, the pipes smoke "raw" until a layer of carbon is built up on the inside surface, a process that could take several days or even weeks.